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<html lang="en">
<head>
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    <title>Document</title>
</head>
<style>
*{margin: 0;padding: 0;}
.container{
    width: 100%;
    margin: 0 auto;
}
img{
    width: 100%;
    display: block;
}
</style>
<body>
<div class="container">
    <!-- <img src="img/400.webp" srcset="img/800.webp 800w,img/1600.jpg 1600w" alt=""> -->
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        <source srcset="img/800.webp" media="(min-width:50em)">
        <source srcset="img/1600.jpg" media="(min-width:30em)">
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    </picture>
</div>
<script src="js/picturefill.js"></script>
</body>

</html>